package com.hmdp.service.impl;

import cn.hutool.core.bean.BeanUtil;
import com.hmdp.dto.Result;
import com.hmdp.entity.VoucherOrder;
import com.hmdp.mapper.VoucherOrderMapper;
import com.hmdp.service.ISeckillVoucherService;
import com.hmdp.service.IVoucherOrderService;
import com.baomidou.mybatisplus.extension.service.impl.ServiceImpl;
import com.hmdp.utils.RedisIdWorker;
import com.hmdp.utils.UserHolder;
import lombok.extern.slf4j.Slf4j;
import org.redisson.api.RLock;
import org.redisson.api.RedissonClient;
import org.springframework.aop.framework.AopContext;
import org.springframework.core.io.ClassPathResource;
import org.springframework.data.redis.connection.stream.*;
import org.springframework.data.redis.core.StringRedisTemplate;
import org.springframework.data.redis.core.script.DefaultRedisScript;
import org.springframework.stereotype.Service;
import org.springframework.transaction.annotation.Transactional;

import javax.annotation.PostConstruct;
import javax.annotation.Resource;
import java.time.Duration;
import java.util.Collections;
import java.util.List;
import java.util.Map;
import java.util.concurrent.*;

/**
 * <p>
 * 服务实现类
 * </p>
 *
 * @author 虎哥
 * @since 2021-12-22
 */
@Service
@Slf4j
public class VoucherOrderServiceImpl extends ServiceImpl<VoucherOrderMapper, VoucherOrder> implements IVoucherOrderService {

    @Resource
    private ISeckillVoucherService seckillVoucherService;
    @Resource
    private RedisIdWorker redisIdWorker;
    @Resource
    private StringRedisTemplate stringRedisTemplate;
    @Resource
    private RedissonClient redissonClient;

    private static final ExecutorService SECKILL_ORDER_EXECUTOR =Executors.newSingleThreadExecutor();
    private static final String queueName = "stream.orders";
    @PostConstruct
    public void init() {
        //执行线程任务
        SECKILL_ORDER_EXECUTOR.submit(new VoucherOrderHandler());
    }

    private class VoucherOrderHandler implements Runnable {
        @Override
        public void run() {
            // 初始化消费者组
            try {
                // 创建消费者组，如果组已存在则忽略错误
                stringRedisTemplate.opsForStream().createGroup(queueName, "g1");
            } catch (Exception e) {
                log.warn("消费者组 g1 已存在，跳过创建");
            }
            while (true) {
                try {
                    //1.获取消息队列中的订单信息 XREADGROUP GROUP g1 c1 COUNT 1 BLOCK 2000 STREAMS stream.orders >
                    List<MapRecord<String, Object, Object>> list = stringRedisTemplate.opsForStream().read(
                            Consumer.from("g1", "c1"),
                            StreamReadOptions.empty().count(1).block(Duration.ofSeconds(2000)),
                            StreamOffset.create(queueName, ReadOffset.lastConsumed())
                    );
                    //2.判断消息获取是否成功
                    if (list == null || list.isEmpty()) {
                        //2.1如果获取失败，说明没有消息，继续下一次循环
                        continue;
                    }
                    //3解析消息中的订单信息
                    MapRecord<String, Object, Object> record = list.get(0);
                    Map<Object, Object> values = record.getValue();
                    VoucherOrder voucherOrder = BeanUtil.fillBeanWithMap(values, new VoucherOrder(), true);

                    //4.如果获取成功，则获取订单
                    handleVoucherOrder(voucherOrder);
                    //5.ACK确认 SACK  stream.orders  g1 id
                    stringRedisTemplate.opsForStream().acknowledge(queueName, "g1", record.getId());
                } catch (Exception e) {
                    log.error("订单处理线程异常", e);
                    handlePendingList();
                }
            }
        }

        private void handlePendingList() {
            while (true) {
                try {
                    //1.获取pending-list中的订单信息 XREADGROUP GROUP g1 c1 COUNT 1 STREAMS stream.orders 0
                    List<MapRecord<String, Object, Object>> list = stringRedisTemplate.opsForStream().read(
                            Consumer.from("g1", "c1"),
                            StreamReadOptions.empty().count(1),
                            StreamOffset.create(queueName, ReadOffset.from("0"))
                    );
                    //2.判断消息获取是否成功
                    if (list == null || list.isEmpty()) {
                        //2.1如果获取失败，说明pending-lis没有消息，结束循环
                        break;
                    }
                    //3解析消息中的订单信息
                    MapRecord<String, Object, Object> record = list.get(0);
                    Map<Object, Object> values = record.getValue();
                    VoucherOrder voucherOrder = BeanUtil.fillBeanWithMap(values, new VoucherOrder(), true);

                    //4.如果获取成功，则获取订单
                    handleVoucherOrder(voucherOrder);
                    //5.ACK确认 SACK  stream.orders  g1 id
                    stringRedisTemplate.opsForStream().acknowledge(queueName, "g1", record.getId());
                } catch (Exception e) {
                    log.error("处理pending-list订单异常", e);
                    try {
                        Thread.sleep(20);
                    } catch (InterruptedException ex) {
                        throw new RuntimeException(ex);
                    }

                }
            }

        }
    }

    //阻塞队列
//    private BlockingQueue<VoucherOrder> orderTasks = new ArrayBlockingQueue<>(1024 * 1024);
//    private class VoucherOrderHandler implements Runnable {
//
//        @Override
//        public void run() {
//            while (true) {
//                try {
//                    //1.从阻塞队列中获取订单信息
//                    VoucherOrder VoucherOrder = orderTasks.take();
//                    //2.创建订单
//                    handleVoucherOrder(VoucherOrder);
//                } catch (Exception e) {
//                    log.error("订单处理线程异常", e);
//                }
//            }
//        }
//    }
    private void handleVoucherOrder(VoucherOrder voucherOrder) {
        //1.获取用户
        Long userId = voucherOrder.getUserId();
        //创建锁对象
        RLock lock = redissonClient.getLock("lock:order:" + userId);
        //获取锁
        boolean islock = lock.tryLock();
        //判断是否获取到锁
        if (!islock) {
            log.error("不允许重复下单");
            return;
        }
        try {
            proxy.createVoucherOrder(voucherOrder);
        } finally {
            lock.unlock();
        }
    }

    //在主线程池获取代理对象
    private IVoucherOrderService proxy;
    //加载 判断秒杀券库存是否充足，并且判断用户是否已下单的Lua脚本
    private static final DefaultRedisScript<Long> SECKILL_SCRIPT;

    static {

        SECKILL_SCRIPT = new DefaultRedisScript<>();
        SECKILL_SCRIPT.setLocation(new ClassPathResource("seckill.lua"));
        SECKILL_SCRIPT.setResultType(Long.class);
    }

    @Override
    @Transactional
    public Result seckillVoucher(Long voucherId) {
        //1.执行lua脚本
        Long userId = UserHolder.getUser().getId();
        long orderId = redisIdWorker.nextId("order");
        Long result = stringRedisTemplate.execute(SECKILL_SCRIPT, Collections.emptyList(),
                voucherId.toString(), userId.toString(), String.valueOf(orderId));
        //2.判断结果是否为0
        int r = result.intValue();
        if (r != 0) {
            //2.1如果为0，代表没有购买资格
            return Result.fail(r == 1 ? "库存不足" : "不能重复下单");
        }
        //获取代理对象（事务）
        proxy = (IVoucherOrderService) AopContext.currentProxy();
        //3.返回订单id
        return Result.ok(0);

//        //1.执行lua脚本
//        Long userId = UserHolder.getUser().getId();
//        Long result = stringRedisTemplate.execute(SECKILL_SCRIPT, Collections.emptyList(),
//                voucherId.toString(), userId.toString());
//        //2.判断结果是否为0
//        int r = result.intValue();
//        if (r != 0) {
//            //2.1如果为0，代表没有购买资格
//            return Result.fail(r == 1 ? "库存不足" : "不能重复下单");
//        }
//        //2.2如果不为0，代表有购买资格，把下单信息保存到阻塞队列
//        VoucherOrder voucherOrder = new VoucherOrder();
//        //订单id
//        long orderId = redisIdWorker.nextId("order");
//        voucherOrder.setId(orderId);
//        //用户id
//        voucherOrder.setUserId(userId);
//        //优惠券id
//        voucherOrder.setVoucherId(voucherId);
//        //2.3创建阻塞队列,将订单信息放入阻塞队列
//        orderTasks.add(voucherOrder);
//        //获取代理对象（事务）
//        proxy = (IVoucherOrderService) AopContext.currentProxy();
//        //3.返回订单id
//        return Result.ok(0);

    }

    @Transactional
    public void createVoucherOrder(VoucherOrder voucherOrder) {
        //5一人一单
        Long userId = voucherOrder.getUserId();
        //5.1查询订单
        Integer count = query().eq("user_id", userId).eq("voucher_id", voucherOrder.getVoucherId()).count();
        //5.2判断是否存在
        if (count > 0) {
            log.error("用户已经购买过一次！");
            return;
        }
        //6扣减库存
        boolean success = seckillVoucherService.update()
                .setSql("stock = stock - 1")
                .eq("voucher_id", voucherOrder.getVoucherId())
                .gt("stock", 0)
                .update();
        if (!success) {
            log.error("库存不足");
            return;
        }

        //保存订单
        save(voucherOrder);

    }

//    @Override
//    public Result seckillVoucher(Long voucherId) {
//        //1查询优惠券
//        SeckillVoucher voucher = seckillVoucherService.getById(voucherId);
//        //2.判断秒杀时间是否在有效期内
//        if (voucher.getBeginTime().isAfter(LocalDateTime.now())) {
//            return Result.fail("秒杀时间未到");
//        }
//        //3判断秒杀是否结束
//        if (voucher.getEndTime().isBefore(LocalDateTime.now())) {
//            return Result.fail("秒杀已结束");
//        }
//        //4判断库存是否充足
//        if (voucher.getStock() < 1) {
//            return Result.fail("库存不足");
//        }
//
//        //7返回订单号
//        Long userId = UserHolder.getUser().getId();
//       synchronized (userId.toString().intern()){
//            //获取代理对象（事务）
//            IVoucherOrderService proxy = (IVoucherOrderService) AopContext.currentProxy();
//            return proxy.createVoucherOrder(voucherId);
//
//        }
//        //创建锁对象
////        SimpleRedisLock lock = new SimpleRedisLock("order:" + userId, stringRedisTemplate);
//        RLock lock = redissonClient.getLock("lock:order:" + userId);
//        //获取锁
//        boolean islock = lock.tryLock();
//        //判断是否获取到锁
//        if (!islock) {
//            return Result.fail("不允许重复下单");
//        }
//        try {
//            //获取代理对象（事务）
//            IVoucherOrderService proxy = (IVoucherOrderService) AopContext.currentProxy();
//            return proxy.createVoucherOrder(voucherId);
//        } finally {
//            lock.unlock();
//        }
//    }

//    @Transactional
//    public Result createVoucherOrder(Long voucherId) {
//        //5一人一单
//        Long userId = UserHolder.getUser().getId();
//        //5.1查询订单
//        Integer count = query().eq("user_id", userId).eq("voucher_id", voucherId).count();
//        //5.2判断是否存在
//        if (count > 0) {
//            return Result.fail("用户已经购买过一次！");
//        }
//        //6扣减库存
//        boolean success = seckillVoucherService.update()
//                .setSql("stock = stock - 1")
//                .eq("voucher_id", voucherId)
//                .gt("stock", 0)
//                .update();
//        if (!success) {
//            return Result.fail("库存不足");
//        }
//
//        //保存订单
//        save(voucherOrder);
//        return Result.ok(orderId);
//    }


}

